But in a Sunday-night Instagram post, Swift said she was spurred to speak out in opposition to the Republican congresswoman Marsha Blackburn, who represents Tennessee's 7th District in the US House, saying Blackburn's voting record "appalls and terrifies me."

Swift on Sunday endorsed Bredesen along with Rep. Jim Cooper, the Democrat who represents Tennessee's 5th District, which includes Nashville. She also spoke out in favor of LGBT rights, gender and racial equality, and equal pay for men and women.

In response, various 4chan users derided Swift, many using explicit language including homophobic and racial slurs, and at times called for violence against her.

One wrote that Swift was "pro- f-- and anti-racist" — using a derogatory word for gay people — "so she must be executed."

Another wrote: "What a traitor b----. the trump curse will take her now."

Multiple threads on the website containing hundreds of responses discussed the subject.

In her Sunday post, Swift acknowledged her hesitancy to discuss politics.

"In the past I've been reluctant to publicly voice my political opinions, but due to several events in my life and in the world in the past two years, I feel very differently about that now," she wrote.

Swift's political silence bizarrely led to her becoming a symbol for the white-supremacist movement even though she never publicly endorsed its values.

Last year, Swift threatened to sue a blogger who, when criticizing her silence on political issues in 2017, accused her of enabling a white supremacist fan base to exist around her.

The far-right provocateur Milo Yiannopoulos wrote for the far-right news site Breitbart in 2016 that Swift had a sizable fan club among those identifying themselves in the alt-right movement, as she is "very white and very blonde" and "isn't very forthcoming about her political or religious views."

He said that the association was a joke for some but that many took it seriously. "Like the alt-right itself," he said, "the far-right internet's love affair with this pop star is predominantly sincere but with a heady whiff of satire and troublemaking."

At the same time, Swift's rare political statements have long skewed liberal. In March, she endorsed the March for Our Lives, a national movement calling for increased gun control.